SPDY not working - could be NPN extensions but everything up to date?

[luxpir]

• Ubuntu 12.04 LTS
• Nginx 1.7.12 (upgraded today from Ubuntu mainline/dev PPA)
• OpenSSL 1.0.1 (build from 19/03/15 - upgraded today)

Have restarted Dovecot/Postfix/PHP5-FPM/Monit and of course Nginx. Spdycheck.org is showing no spdy due to no NPN (but this version of openssl supports it, checked changelog), the Chrome/FF extensions also reporting no spdy. SSL Labs are reporting 'No' for NPN.

Have tried adding the 'add_header Alternate ... npn-spdy/3' line to nginx.conf, my enabled config and also to drupal.conf in apps/drupal. Oh, and also trying to get HSTS working with no joy either. Using the line provided in microcache_fcgi.conf.

What am I doing wrong?

EDIT: Have obviously included the listen line as follows in the sites-enabled:

listen 443 ssl spdy default_server;

[server_name, limit_con, log, keepalive_timeout, ssl certs...]

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains";
add_header Alternate-Protocol  443:npn-spdy/3;

[luxpir]

Fixed, strangely, by rebooting the server, as per:

https://www.digitalocean.com/community/questions/simple-spdy-implementation-not-working

Odd solution for a Linux box, but that was it!